Combustion chamber arrangements of this kind for gas turbines are known in the prior art. A mixture of an oxygenous fuel gas and a propellant is ignited in the burners and combusted in the combustion chambers and the expanding hot gases are deflected by the transition sections of the individual combustion chambers toward the turbine chamber and the arrangement of vanes and blades located therein. The streams of hot gas with a circular cross-section generated in the typically cylindrical inlet sections of the individual combustion chambers are thereby transformed by the transition sections into a hot gas stream with a ring-segment-shaped cross-section and finally combined into a circular hot gas stream. This passes through the annular gap into the turbine chamber and drives the blades of the gas turbine.
The heat released during combustion of the fuel gas/propellant mixture causes the individual combustion chambers to be heated to a significant degree, which means that intensive cooling is required in this area. Various cooling principles are proposed for this in the prior art. With a combustion chamber arrangement shown in U.S. Pat. No. 4,719,748 the entire individual combustion chamber is designed with a twin-layer housing, whereby an air gap is left between the individual housing layers. A cooling fluid flows in through openings in the outer housing layer into the intermediate space left between the housing layers and impinges on the inner layer of the individual combustion chamber. This already results in a first cooling effect which is referred to as impingement cooling. The cooling fluid subsequently flows through the intermediate space left between the housing layers and provides convective cooling. This design is also referred to as a closed cooling system on account of the continuous twin-layer configuration of the combustion chamber walls.
Another concept is referred to as open cooling, whereby the individual combustion chambers are configured with a single wall. Cooling fluid flows openly past the individual combustion chambers and has a cooling effect. Because the individual combustion chambers are configured with a single wall, the flow of cooling fluid is not conveyed in a directed and defined manner, resulting in a generally lower level of cooling efficiency. On the other hand such a configuration of the individual combustion chambers is simpler in construction and more economical to manufacture.
From the more recent prior art it is also known that hybrid forms of open and closed cooling systems can be used for the individual combustion chambers. Large areas of the individual combustions chambers are then subject to open cooling, while an area to be cooled by a closed cooling system is created by means of an arrangement of a second wall surrounding the first wall and leaving an intermediate space solely in an area projecting through an outer housing. With this design the individual combustion chambers used are configured with a simple construction as before but the improved cooling effect achieved with a very small area cooled in a quasi-closed manner is not as significant as might be wished.